{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/xfs/libxfs/xfs_exchmaps.c",
            "fs/xfs/libxfs/xfs_log_format.h",
            "fs/xfs/xfs_bmap_util.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be",
              "status": "affected",
              "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42",
              "versionType": "git"
            },
            {
              "lessThan": "7d3b9b2c9dc57f93f36c716ab752548cb4db9900",
              "status": "affected",
              "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42",
              "versionType": "git"
            },
            {
              "lessThan": "4756c94260e69ce42612b8220c3614f02f7a11d5",
              "status": "affected",
              "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42",
              "versionType": "git"
            },
            {
              "lessThan": "d84d6c1a7f1e2de9e601703a326a4c1b7b421943",
              "status": "affected",
              "version": "f0bc4d134b46607967bda1205ce3226a1bd95f42",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/xfs/libxfs/xfs_exchmaps.c",
            "fs/xfs/libxfs/xfs_log_format.h",
            "fs/xfs/xfs_bmap_util.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.9"
            },
            {
              "lessThan": "4.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.114",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.57",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.11",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "4.9",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: stop exchanging reflink flags when exchanging mappings\n\nWhen an exchange covers both files from offset 0 to i_disk_size,\nxmi_can_exchange_reflink_flags() assumes every mapping moved and hands\nthe reflink flag over to the other file.\n\nThat assumption is wrong.  A file can still own shared blocks past\ni_disk_size, e.g. after EXCHANGE_RANGE_TO_EOF sets a smaller size\nwithout unmapping anything.  The flag is cleared anyway, and the next\nwrite to such a block happens in place instead of CoW, corrupting the\nother file that shares it.\n\nCommit a23eca88448e (\"xfs: fix exchange-range reflink flag clearing\nissue with INO1_WRITTEN\") fixed one instance of this.  Rather than add\nanother special case, stop moving the flags.\nxfs_exchmaps_ensure_reflink() already sets the flag on both inodes\nbefore the exchange, so both just keep it.\n\nNothing sets CLEAR_INO{1,2}_REFLINK anymore.  Intents logged by older\nkernels may still carry them; recovery already masks them off, so they\nstay in the log format mask and are ignored.\n\nXFS_IOC_SWAPEXT has the same problem: it moves the reflink flag from\none inode to the other along with the extents.  Just removing that is\nnot enough here: the exchange path flags both inodes up front in\nxfs_exchmaps_ensure_reflink(), but swapext has no such step, so the\ninode receiving the shared extents would be left without the flag.\nSet it on both inodes instead, and make sure both have a CoW fork,\nsince an inode with the reflink flag is expected to have one.\n\nThe flag now stays until FALLOC_FL_UNSHARE_RANGE, xfs_scrub, or a\ntruncate to zero removes it."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - `ioctl(2)` runs `do_vfs_ioctl()`/`vfs_ioctl()` \u2192 `xfs_file_ioctl()` \u2192 `xfs_ioc_exchange_range()` \u2192 `xfs_exchange_mappings()` \u2192 patched `xfs_exchmaps_init_intent()`; all causal file descriptors, offsets, and flags are supplied locally.\nAC:L - On a reflink/exchange-range XFS, the attacker can clone a target block, use chosen `TO_EOF` offsets to strand it past `i_disk_size`, perform a full-range exchange so `xmi_can_exchange_reflink_flags()` clears the flag, and `pwrite` the shared block; no race or external event is required.\nPR:L - `xfs_exchange_range()` requires only read-write scratch-file descriptors and `remap_verify_area(..., true)`, with no `capable()` check; FICLONE requires only read access to the protected source and write access to an attacker-owned destination.\nUI:N - The attacker personally performs FICLONERANGE, the crafted `XFS_IOC_EXCHANGE_RANGE` operations, and the final `pwrite`; no victim must mount media, open a file, or take another action.\nS:U - `xfs_exchmaps_clear_reflink()` breaks CoW isolation between inodes on the same XFS host; using the resulting protected-file overwrite for root access is a standard local privilege escalation, not a VM, IOMMU, or other security-authority escape.\nC:H - The attacker can clone a readable SUID-root binary, then make the faulty non-CoW write alter its physical block without modifying its inode or clearing SUID metadata; executing the corrupted binary can yield root and unrestricted access to host-confidential data.\nI:H - After `xfs_exchmaps_clear_reflink()` removes the flag, `xfs_is_cow_inode()` is false and the iomap write path updates the still-shared block in place, permitting persistent attacker-controlled modification of readable protected files without write permission.\nA:H - The same in-place primitive can corrupt readable boot-critical executables, and overwriting a SUID-root binary can provide root control capable of stopping the host, supporting complete availability loss."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-24T14:09:45.210Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/1fa2f3a7ef7ee0f2503a4b0afe24bc8c9d0820be"
        },
        {
          "url": "https://git.kernel.org/stable/c/7d3b9b2c9dc57f93f36c716ab752548cb4db9900"
        },
        {
          "url": "https://git.kernel.org/stable/c/4756c94260e69ce42612b8220c3614f02f7a11d5"
        },
        {
          "url": "https://git.kernel.org/stable/c/d84d6c1a7f1e2de9e601703a326a4c1b7b421943"
        }
      ],
      "title": "xfs: stop exchanging reflink flags when exchanging mappings",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98975",
    "datePublished": "2026-10-23T12:19:48.379Z",
    "dateReserved": "2026-09-25T10:25:14.383Z",
    "dateUpdated": "2026-10-24T14:09:45.210Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}